In an inkjet recording apparatus, which is an example of image forming apparatuses including printers, facsimile machines, and copy machines, a liquid discharge head is used as a recording head. The liquid discharge head discharges ink as a recording liquid onto a sheet to form (i.e., record, print, or transcribe) an image. The “sheet” herein is not limited to a sheet of paper but it includes any medium onto which a droplet of ink or other liquid can attach. Thus, the sheet may also be referred to as a “recorded medium,” a “recording medium,” a “recording paper,” or a “recording sheet.”
In such an image forming apparatus, a user may use ink other than a specific ink, such as a manufacturer's designated ink, a “recommended” ink, or a “genuine” ink. While this can be a cause for troubles such as image defect or failure, some users prefer non-genuine products for cost-reducing purposes, aware of the potential troubles that the non-specific item may cause. Some other users may purchase and use non-genuine products without knowing it. Technologies for preventing the use of products other than a specific product are proposed in Japanese Laid-Open Patent Applications No. 2000-326518 and 2004-188635; Japanese Patent No. 3095008; and Japanese Laid-Open Patent Application No. 2001-075455.
Japanese Laid-Open Patent Application No. 2006-276709 discloses an image forming apparatus in which use of a non-genuine product can be appropriately reflected in leasing charge. Japanese Laid-Open Patent Applications No. 2005-288845 and 2005-193522 disclose image forming apparatuses in which, instead of restricting a printing operation, a maintenance operation is performed to prevent failure or other troubles upon detection of use of a non-genuine product.
Although measures have been taken from the maintenance aspect as mentioned above in response to the use of non-specific products, no consideration is given with regard to the quality of an output image. As a practical matter, differences in ink material may lead to problems such as a failure to discharge an intended amount of ink, or a drop in landing position accuracy. Furthermore, because the amount of ink that a sheet can absorb varies depending on the type of ink, the probability of image quality deterioration such as beading increases when an excessive amount of ink attaches to the sheet.
In some inkjet printers, a recording head and an ink tank are integrated. In this case, a user may also use a recording head other than a specific head, such as one recommended by the manufacturer. If that happens, an intended amount of ink may not be discharged, or landing position accuracy may decrease.
Another example of the potential use of a non-specific product is the recording media (such as a sheet of paper). Many users are unaware of the characteristics of a recording medium they print on. Many users also tend to select non-specific recording media, which may be called a “glossy sheet,” a “photographic sheet,” or a “high-quality paper,” simply because they are less expensive. In such a case too, because different sheets have different ink absorption amounts, excessive ink attachment may occur, resulting in beading or other image quality degradation. Because such various recording media also have different thicknesses, it may become impossible to cause an ink droplet to become attached to a target landing position.
Thus, the image quality may greatly drop below the optimum quality when even any one of the factors of ink, recording head, and recording medium is changed.
It is therefore a general object of the present invention to overcome the aforementioned problems. A more specific object is to provide an image forming apparatus capable of producing a high-quality image even when an expendable supply such as ink, a recording head, or a recording medium that is not a specific product is used.